bug#4033: 23.1; list-colors-display is misleading

[Drew Adams]

emacs -Q
M-x list-colors-display
 
The RGB values listed at the right side are misleading.
 
I have had at least one user state that he thought that, since the
form shown is #RRGGBB, his colors had only that granularity.  IOW,
even if one's system allows colors of the form #RRRRGGGGBBBB (more
colors), the color names are translated to hex strings of the form
#RRGGBB (fewer colors).
 
The displayed RGB hex string ideally should reflect the user's actual
color possibilities.  If there is no way for Emacs to know that, then
it's better to err on the side of providing more information:
#RRRRGGGGBBBB, rather than less: #RRGGBB.  E.g., it's better to
translate LightBlue as #befded5effff than as #beedff.
 
And if the user's real color space cannot be known, then a note/legend
should be added (at least in the `C-h m' help for the
`list-colors-display' buffer, but preferably at the top or bottom of
the buffer itself), saying that the RGB code shown is not necessarily
representative of the color granularity for your system.
 

In GNU Emacs 23.1.1 (i386-mingw-nt5.1.2600)
 of 2009-07-29 on SOFT-MJASON
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.4)'